How to keep a house cool when outside temperatures rise

woman sitting next to an open window trying to keep cool
(Image credit: Getty)

While there hasn't been much call to find out how to keep a house cool yet this summer, things do look set to change — we hope.

With temperatures expected to rise in the coming days and weeks, the subject of  how to prevent overheating in homes is bound to crop up. The barbecues will undoubtedly be dusted off, the paddling pools inflated and the patios hosed down — but there is a less pleasant side of summer to bear in mind along with all this fun.

Trying to get every day tasks carried out in a swelteringly hot house can be tough, while getting a good night's sleep on hot sticky nights is nigh on impossible. Fear not though, there are plenty of easy ways to keep a house cool in summer and we've gathered them all up into this handy collection of top tips, from hacks to upgrade a standard electric fan to through to taking a fabric first approach to house design, we've got it all. 

How to keep a house cool in summer with good design

One of the best ways to prevent a house from overheating is to take a fabric first approach to its design. 

This basically means you use the design, components and materials of the house –the items that make up the building's fabric – to maximise its performance. Although this is an idea that will work best for self builders – and is now enshrined in the Building Regulations Part O – it can also be used when adding an extension and, to a degree, by renovators too.

Incorporating shading into the house's design, such as overhangs or a brisé soliel, using windows with low g-values, recessing windows, building balconies to shade the glazed areas below and orientating the building to benefit from shading by nearby buildings and trees are all great ways to ensure your house stays at a comfortable temperature year round.

self build house with zinc roof and balcony

Incorporating shading into the design of your home will help to prevent overheating.  (Image credit: Fraser Marr)

1. Learn how to create a cross breeze

Creating a cross breeze or cross ventilation in your home, or in just one room, is a cheap and effective way to cool your rooms naturally. 

In order to make this cooing magic happen, open the windows on the side of the house that the wind is blowing from — then simply open the windows or doors on the opposite side of the space. If you only have windows on one side of the room you are trying to cool, open the door on an opposite wall instead and open the window in the next room along.

By doing this you will create a current of air that sweeps across the room. This natural ventilation will take hot, stale air with it and expel it through the opposite opening. 

Certain types of window are more effective when trying to cross ventilate a room than others — top hung windows and sash windows are ideal. As hot air rises, by opening the lower section of a window on the side of the house the breeze is coming from and then the top half of the opposite window, any warm air that has gathered towards the top of the room will be forced out.

creating a cross breeze by opening a window

Creating a cross breeze is a simple yet effective method of cooling down a room fast.  (Image credit: Getty)

2. Use curtains and blinds to shade rooms

This may be an obvious tip but it is a good one nonetheless. Drawing your curtains or pulling your blinds in the rooms subject to the greatest amounts of sunlight will really keep them cool — this is particularly important in bedrooms that get the sun throughout the afternoon if you want them to be bearable sleeping spots when night falls. 

You can boost the effectiveness of this tip by investing in thermal blinds and curtains, or blackout versions. 

reading corner with large windows

Simply drawing your curtains to keep out the heat will go a long way towards keeping your house cool.  (Image credit: Cafe Latte)

3. Reap the benefits of a good electric fan

This might not be the most energy-saving way of cooling a house out there but an electric fan directed wisely can really offer a huge amount of cooling power on hot nights. 

Given their high energy consumption, it pays to ensure you are using them in the most effective way possibly. Direct them upwards to make the most of the cooler air in your home, which will settle at floor level, and ensure no large items of furniture are blocking the flow of air produced. 

The Honeywell TurboForce Power Fan from Amazon is highly praised by users for its quiet operation and effectiveness. 

You can also turn a regular fan into an 'ice fan' for a lovely chilly blast by positioning a bowl of cold water filled with ice in front of the fan blades (ensure you do so safely) — frosty water particles will be scattered around the room. 

woman using electric fan to cool down

While electric fans don't cool down a room, they do help to cool down the person using them.  (Image credit: Getty)

4. Change old windows for more energy efficient versions

While you may only have thought of double and triple glazed windows as methods of keeping your house warmer in winter, they can also keep it cooler in summer. 

These types of glazing basically stop heat transferring from inside to out and vice versa.

If you want to take your glazing upgrade one step further, if perhaps you are self building or extending or taking on an extensive renovation project, you might like to consider solar control glass. 

5. Upgrade your loft insulation

If you have ever ventured into your loft on a hot day you may have been greeted by a blast of hot air. Likewise, have you ever noticed how your upstairs rooms get warmer than those downstairs?

One reason for this is that as the sun shines on to your roof (particularly if your roofing materials are dark in colour), heat is absorbed and transferred into the loft space. Without proper loft insulation this heat will then radiate into your upstairs rooms. 

Once you've found out how to insulate a loft (which is a task within the remit of most DIYers) it's worth noting that rolls of insulation should be laid to create a depth of 250 - 270mm thick, laid evenly across the loft space. 

Man preparing to insulate loft in house

Insulating your loft properly will really help keep the upstairs of your home cooler.  (Image credit: Getty Images)

6. Take a look at portable air conditioning units

Portable air conditioning units are one up from an electric fan when it comes to their cooling abilities — but they are also less expensive than retrofitting built in air conditioning

Unlike electric fans, which simply blow air around the room, air conditioners actually lower the temperature. They work by taking in air, passing it through a compressor before blowing the cooled air out.  

To ensure you are getting the most for your money (good quality models start from between £200-£500 depending on size) pick on that is big enough for the space you want to cool. 

Portable air conditioners are rated in British Thermal Units (BTU) — the higher the BTU the larger the space that they can cool down. An air conditioner with a 9,000 BTU rating would work in a room of approx. 21m2. 

Do bear in mind that portable air conditioners need to be vented to outside, where the warm, stale air will be expelled — through a window or wall, for example. 

7. Invest in a ceiling fan

Ceiling fan designs have come a long way since the 1970s and there are now some great contemporary models that can really boost the style credentials of your home, as well as how comfortable it feels in hot weather.

Like electric fans, ceiling fans do not actively lower the temperature of a room, they simply create a welcoming breeze.

The best advice is to set your ceiling fan to rotate in a counterclockwise direction in the summer months. This pushes air directly downwards rather than all around the room. 

To save money on running costs, remember to switch fans off when leaving the room — they won't keep it cool anyway as they cool people, not spaces.  

wooden ceiling fan

Ceiling fans are now available in some very striking designs.  (Image credit: Getty)

8. Turn off lights and appliances when not needed

All electrical appliances, when turned on, generate a certain amount of heat. Switching off items such as computers, the television, games consoles and the like will mean your room could well feel a little cooler. 

Chargers will also give out heat — so if you need to top up your mobile battery, do it early in the morning.

Lightbulbs are another culprit when it comes to making a space feel warmer — table lamps next to the bed will really increase any discomfort caused by heat while trying to nod off. 

The type of lightbulb you use will have an impact on how much heat is given off by your light fittings. "Light bulbs radiate heat, which isn’t particularly helpful during a heatwave. Conventional incandescent light bulbs generate light quite inefficiently, giving up to 90 percent of their energy as waste heat in the process," explains Matthew Currington, Technical Director ofThe Lighting Superstore

LED bulbs give off less heat as well as saving you money. 

9. Shade large windows with awnings

Not only are rectractable awnings one of the best patio cover ideas around, they can also help to keep your house cool internally. 

Whether you have a kitchen with a swathe of sliding glass doors or a living room with lots of large windows that faces out to your garden, you may well have felt the 'greenhouse effect' on those sunny days. 

Adding an awning creates a cool, shady spot directly in front of any doors and windows, shielding them from the glare of the sun.

Being retractable, awnings are also a flexible option as they can be neatly tucked away when not in use — cassette awnings, semi-cassette awnings and open awnings are all options. They need not look dated either — there are some great modern deigns now available.

patio doors covered by awnings

Using retractable awnings over large windows and glass doors will prevent the room they are in from overheating.  (Image credit: Thomas Sanderson)

10. Fit solar control window film

If you have large amounts of glazing, or glass ceilings, applying a solar control window film is an inexpensive and easy way to ensure your rooms won't overheat — plus you can still enjoy views to outside. 

Most are designed to be stuck to the glass, internally or externally, and they come with a range of benefits, such as UV control and heat rejection. 

For those building new homes, conservatories or extensions, particularly those orientated south, consider solar control glass.

large sliding doors and glass ceiling

If you are fitting new patio doors, consider opting for solar control glass if they will face south. (Image credit: Purlfrost)
Natasha Brinsmead

Natasha is Homebuilding & Renovating’s Associate Content Editor and has been a member of the team for over two decades. An experienced journalist and renovation expert, she has written for a number of homes titles. Over the years Natasha has renovated and carried out a side extension to a Victorian terrace. She is currently living in the rural Edwardian cottage she renovated and extended on a largely DIY basis, living on site for the duration of the project. She is now looking for her next project — something which is proving far harder than she thought it would be.